Wireless Communication David Kopczyk

AM/FM Most current wireless tech utilizes FM Radio Transmission

Uses different bands split into channels b - 2.4GHz, 22MHz channels g - 2.4GHz, 20MHz channels n - 2.4/5GHz, 20/40MHz channels ac - 5GHz, 20/40/80/160MHz channels Utilizes beacon frames to advertise devices Wi-fi

Consists of header, body, and CRC field Body Contents: Capability Information (2 bytes) -capability of network using bitmasks Beacon Frame

Timestamp (8 bytes) -uses Kilo-microsecond (TU) Beacon Interval (2 bytes) -also uses TU SSID Supported data rates Beacon Frame

2.4GHz band, 79 1MHz channels Channel-hops 1600 times a second Bluetooth Basics

1. Access Code: It is 72 bit field that contains synchronization bits. It identifies the master. 2. Header: This is 54-bit field. It contain 18 bit pattern that is repeated for 3 time. The header field contains following subfields: (i) Address: This 3 bit field can define up to seven slaves (1 to 7). If the address is zero, it is used for broadcast communication from primary to all secondaries. (ii)Type: This 4 bit field identifies the type of data coming from upper layers. (iii) F: This flow bit is used for flow control. When set to 1, it means the device is unable to receive more frames. (iv) A: This bit is used for acknowledgement. (v) S: This bit contains a sequence number of the frame to detect retransmission. As stop and wait protocol is used, one bit is sufficient. (vi) Checksum: This 8 bit field contains checksum to detect errors in header. 3. Data: This field can be 0 to 2744 bits long. It contains data or control information coming from upper layers Bluetooth Frame

Uses Bluetooth Low-Energy (BLE) Broadcasts a single frame every second Frame contains: UUID Major ID Minor ID Transmitted power iBeacon

02 # Number of bytes that follow in first AD structure 01 # Flags AD type 1A # Flags value 0x1A = bit 0 (OFF) LE Limited Discoverable Mode bit 1 (ON) LE General Discoverable Mode bit 2 (OFF) BR/EDR Not Supported bit 3 (ON) Simultaneous LE and BR/EDR to Same Device Capable (controller) bit 4 (ON) Simultaneous LE and BR/EDR to Same Device Capable (Host) 1A # Number of bytes that follow in second (and last) AD structure FF # Manufacturer specific data AD type 4C 00 # Company identifier code (0x004C == Apple) 02 # Byte 0 of iBeacon advertisement indicator 15 # Byte 1 of iBeacon advertisement indicator e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a e0 # iBeacon proximity uuid # major # minor c5 # The 2's complement of the calibrated Tx Power iBeacon Frame

Open-source community response to Apple’s patent Same as iBeacon, but can also transmit additional data fields Altbeacon

Titanium Mobile SDK Android Library Documentation Module Code Sample Code Altbeacon Spec Demo